This invention relates to new catalysts, a process for preparing the catalyst, and use of the catalysts. In one aspect, the invention relates to a high surface area catalyst support or component prepared by swelling a magnesium dihalide with a secondary or tertiary alcohol. In another aspect, this invention relates to a catalyst prepared by swelling a particulate magnesium dihalide with a secondary or tertiary alcohol followed by removal of unreacted alcohol and treatment with a titanium tetrahalide. In another aspect, this invention relates to the formation of a magnesium dihalide catalyst component and catalyst composition as defined above which can be used with a cocatalyst comprising a metallic hydride or an organometallic compound to form a catalyst system useful for the polymerization of alpha-olefins. In a further aspect, this invention relates to a process for forming a catalyst system produced by swelling a particular magnesium dihalide with a secondary or tertiary alcohol, adding a hydrocarbon diluent, and removing some or substantially all of the alcohol, and contacting the product thus formed with a halogenated tetravalent titanium compound to form a first catalyst component.
It is known to polymerize alpha-olefins and mixtures thereof according to a low pressure process in which the catalysts used are prepared from mixtures of compounds of element of Subgroups IV--VI of the Periodic Table and organometallic compounds of the elements of Groups I-III of the Periodic Table. The polymerization is generally carried out in suspension, in solution, or even in a gaseous phase.
The activity of an olefin polymerization catalyst is one important factor in the continuous search for a catalyst useful for the polymerization of alpha-olefins. It is also desirable that the process used in forming catalyst be such as to allow ease in preparation and to allow control over the final catalyst formed. It is also desirable to produce a catalyst of the organometallic type that comprises chiefly an inert support which is not harmful when left in the polymer. It is also advantageous to prepare a catalyst containing low amounts of residual materials whereby deashing of the produced polymer can be eliminated and a simple deactivation of the residual catalyst is all that is required. The present invention relates to an improved catalyst exhibiting increased activity and possessing some of the above mentioned advantages.
Accordingly, an object of this invention is to provide an improved catalyst.
Another object of this invention is to provide a high surface area metal halide suitable as a catalyst component or support.
Another object of this invention is to provide a process for preparing a novel catalyst.
Another object of this invention is to provide an improved process for the polymerization of alpha-olefins.
Other objects, aspects and the several advantages of this invention will be apparent to those skilled in the art upon a study of this disclosure and the appended claims.